Disney measles outbreak grows in California, Mexico infant infected

The measles outbreak linked to the Disney theme parks, Disneyland and Disney California Adventure, has affected more people in the Golden State, and has even been attributed to a case south of the border.

Nearly half the cases reported are in individuals 20 years of age or older, although the data is lacking age groups for several patients.

Health officials report the measles outbreak exposure period of December 17 – 20 at the Disneyland Resort is over, and all cases from this exposure should have occurred by January 10, 2015. No new cases have been identified in guests who visited after that time period.

Measles is highly contagious. It’s spread by air, and so contagious that if an infected person enters a room, leaves, and an unvaccinated person enters the room hours later, they still can contract measles. Remember a few months back, when that figure was circulating showing thatEbola wasn’t particularly easy to spread? Well, measles very much is. The basic reproductive rate for Ebola is around 2, meaning on average each infected person will cause an additional 2 infections in susceptible individuals.

And what’s the reproductive number for measles?

Eighteen. Eight. Teen. I’m not exaggerating when I say that it is literally one of the most contagious diseases we know of. On average, if you have 10 susceptible individuals exposed to a measles patient, 9 will end up getting sick.

The CDPH says the only way to prevent measles is through immunization, and this outbreak is a reminder that measles is just a plane ride away from the United States.